�1���� Scope
�2����
References
�3����
Definitions
�4����
Description of model
������� 4.1���� Overview
������� 4.2���� Echo control requirements
������� 4.3���� Round-trip delay criteria
������� 4.4���� Modem impedance requirements
������� 4.5�� ��Model limitations
������� 4.6���� Digital impairment requirements
������� 4.7���� Network Model Coverage (NMC)
�5����
Impairment level set-up
Annex�
A � Attenuation and envelope delay distortion
characteristics
Annex�
B � Minimizing test time
Appendix� I � Rare
intracontinental network model
������� I.1���� Model description
Appendix�
II � Basis for network models
Appendix�
III � Error rate vs. network model coverage
����� III.1���� Bit- and block-error rate vs. network model coverage
Appendix� IV � Supplemental
round trip delay model